The present invention relates to a pin and socket type, wet-mateable connector for making electrical and fiber-optic cable connections in a harsh environment, such as an underwater or deep sea environment, a splash zone, or other harsh or hazardous environment. .
Both electrical and optical cables are now commonly used in undersea environments for various applications, such as telecommunications, oceanography, submarine systems, and subsea oil and gas development. There are many problems inherent in successfully mating electrical and optical circuits or cables underwater, particularly in ensuring adequate, reliable sealing and protection of the optical contact faces at deep sea depths.
Current underwater connectors typically comprise releasably mateable plug and receptacle units, each containing one or more electrical or optical contacts or junctions for engagement with the junctions in the other unit when the two units are mated together. The contacts on one side are in the form of pins or probes, while the contacts or junctions on the other side are in the form of sockets for receiving the probes. Typically, the socket contacts are contained in a sealed chamber containing dielectric fluid, and the probes enter the chamber via one or more sealed openings. One major problem in designing such units is the provision of seals which will adequately exclude seawater from the contact chamber after repeated mating and demating.
In some known underwater electrical connectors, such as the connector described in U.S. Pat. No. 5,645,442 of Cairns, the receptacle unit has a stopper which is positioned in sealing engagement with an annular end seal when the units are not mated. The chamber sealed by the stopper and end seal contains a circuit contact and dielectric fluid. As the plug probe enters the chamber, it pushes the stopper back, enters the inner chamber, and makes electrical contact with the circuit connection. At the same time, the end seal will seal against the plug probe to ensure that water cannot enter the chamber. This provides a robust and reliable electrical connector for use in harsh, deep sea environments, but it cannot accommodate optical circuits
U.S. Pat. No. 6,017,227 of Cairns et al. describes a hybrid, wet-mateable electro-optical connector which has oil-filled and pressure-balanced plug and receptacle units, together with a rolling seal arrangement for sealing the oil-filled chamber of each unit when unmated. Within the internal oil chambers of both units, groups of contact junctions are aligned behind cylindrical seals which are mounted in seats in the front face of each unit. As the units are mated together, projecting portions of the cylindrical seals engage and press against each other, forcing water out from between them. As the mating sequence continues, actuators engage the two rolling seals to rotate them in unison, transporting any trapped debris to one side, and at the same time aligning openings in the seals with the oil-filled chambers. Probes in one unit then extend through the aligned seal openings into the chamber in the other unit, contacting sockets within the receptacle. This connector may be used for optical or electrical circuits, or both optical and electrical circuits. It ensures that none of the contacts are ever exposed to the outside environment, whether before, during, or after mating.
Although the rolling seal connector provides an extremely reliable sealing mechanism which can withstand repeated mating and de-mating, it cannot accommodate larger electrical circuits of relatively high voltage. Thus, its capacity for providing an electro-optical junction is limited.